Thionyl Chloride → beta-Carbolin-3-carboxylic acid diethylamide

HRID 1757964Notes

Reaction equation

HRID 1757964 reaction equation
[CH:1]1[C:13]2[NH:12][C:11]3[C:6](=[CH:7][CH:8]=[CH:9][CH:10]=3)[C:5]=2[CH:4]=[C:3]([C:14]([OH:16])=O)[N:2]=1.S(Cl)(Cl)=O>CN(C)C=O>[CH2:1]([N:2]([CH2:3][CH3:4])[C:14]([C:3]1[N:2]=[CH:1][C:13]2[NH:12][C:11]3[C:6]([C:5]=2[CH:4]=1)=[CH:7][CH:8]=[CH:9][CH:10]=3)=[O:16])[CH3:13]

Participants

4

Reactant 2

HCID 24386Thionyl ChlorideHCID 1732629H-Pyrido(3,4-b)indole-3-carboxylic acid

Product 1

HCID 54101367beta-Carbolin-3-carboxylic acid diethylamide

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

A mixture of 2 g of β-carbolin-3-carboxylic acid, 20 ml of thionyl chloride and 2 ml of dimethylformamide is boiled under reflux for 1 hour. The excess thionyl chloride is removed by distillation under reduced pressure. 20 ml of diethylamine is added under cooling to a suspension of the residue in 20 ml of triethylamine and the mixture is concentrated under reduced pressure. The residue is treated with aqueous ammonia (pH 8.5) and the mixture thus obtained is extracted with chloroform (6×25 ml). The extract is washed with water (2×25 ml), dried (K2CO3), decolorized with a small amount of charcoal and filtered. The filtrate is evaporated to dryness and the residue is kept at 60° C. overnight. The solid (1.56 g; 62%) is recrystallized from toluene to form β-carbolin-3-carboxylic acid diethylamide having a melting point of 170.0° C.

Workup

  1. temperatureunder reflux for 1 hour
  2. customThe excess thionyl chloride is removed by distillation under reduced pressure
  3. addition20 ml of diethylamine is added
  4. temperatureunder cooling to a suspension of the residue in 20 ml of triethylamine
  5. concentrationthe mixture is concentrated under reduced pressure
  6. additionThe residue is treated with aqueous ammonia (pH 8.5)
  7. customthe mixture thus obtained
  8. extractionis extracted with chloroform (6×25 ml)
  9. washThe extract is washed with water (2×25 ml)
  10. dry with materialdried (K2CO3)
  11. filtrationfiltered
  12. customThe filtrate is evaporated to dryness
  13. customThe solid (1.56 g; 62%) is recrystallized from toluene

Sources & evidence

ORD record
ord-d75d7dfb6b6e4a6bb5ad419e29e3ac57
Source dataset
uspto-grants-1983_02
Patent number
US04371536

Reaction notes

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